The percentage of American children from 4 through 17 years of age who have ever been diagnosed with attention-deficit/hyperactivity disorder (ADHD) increased 42 percent from 2003 to 2011, according to a newly released study by the federal Centers for Disease Control and Prevention.

The study indicated that more than 20 percent of 11- and 14-year-old American boys had been diagnosed with ADHD at some point in their lives, that boys were 125 percent more likely than girls to be diagnosed with the disorder, and that boys were 127 percent more likely than girls to be medicated for it.

The study also found that children in public health programs (Medicaid and the State Children’s Health Insurance Program) were 53 percent more likely to be diagnosed with ADHD than children with private health insurance.

“The parent-reported prevalence of a history of an attention-deficit/hyperactivity disorder (ADHD) diagnosis by a health care provider among U.S. school-aged children increased from 7.8% in 2003 to 11% in 2011, an increase of 42% in less than a decade,” said the study published by the Journal of the American Academy of Child & Adolescent Psychiatry.